26mm. Issued in bronze, aluminum and sterling silver versions, only the silver version having any significant value. These sets came in blue library display binders. 25 medals were in each binder. Three series were produced, Series 1, Series 2, and Series 3.
In 1969, the Sun Oil company used the aluminum medals in a promotional program game. There were two series of 25 medals, distinguished by their reverses. Some medals carried an "Instant Winner" reverse, which could be redeemed for cash prizes or bronze sets of medals. Sterling silver sets were offered to collectors.
The collection was available from 1969 to 1970.
The Bronze set consisted of 26 millimeter proofs. Its mintage was 325,024 sets.